ببFluids and Electrolytes وو for nursing .pptx

Nursing College

1. Fluid & Electrolyte balance 1

2. Body Composition Fluid 60% Solid 40 % Fat Protein Carbohydrate Minerals 2

3. Distribution of body fluids (by wt) Fluid 60% of BW I n tracellular Extracellular Intrstitial Intra vascular(plasma) Intracellular 40% 25 L (cytoplasm, nucleoplasm) Intrastitial 15% 12 L (lymph, CSF, synovial fluid, aqueous humor and vitreous body of eyes, between serous and visceral membranes, glomerular filtrate of kidneys. ) Plasma 5% 3 L There is continuous ongoing equilibrium between the intracellular and extracellular spaces. 3 TBW 40 L

4. Fluid content according to age Total body water (TBW) vary with age: Preterm = 80-85% Term = 75% Infant= 65% Older children & adult male= 60% Adult female=50% TBW ↓ to 60% by 1st yr of life Female has less fluid content because of more fat cells 4

5. Effective circulating volume (ECV) Def: Portion of the ECF that take part in tissue perfusion. Only 5% of TBW (intra vascular fluid) are ECV Adequate ECF must be maintained all the times 5

6. Composition of body fluid Water Electrolytes : Inorganic salts, Sodium(Na), Potassium(K), Calcium (Ca), Chloride(Cl), Phosphate(Po4), Bicarbonate(HCO3, Sulphate(SO4) Nonelectrolytes : Minerals -iron and zinc, Glucose, Lipids, Creatinine, Urea 6

7. Electrolytes of body fluid Electrolytes are measured in mEq or mmol Circulating electrolytes electrically charged When positively charge called cation : Na + , K + , Ca ++ When negatively charge called anions : Cl - , HCO3 - , SO4 - 7

8. Electrolytes composition of body fluids Normal Values(serum) Cation : Sodium (Na +) 135 – 145 mEq/L Potassium (K + ) 3.5 – 5.50 mEq/L Calcium (Ca ++ ) 8.5 – 10.5 mg/dL Ionized Calcium 4.5 – 5.5 mg/dL Magnesium (Mg++) 1.5 – 2.5 mEq/L Anion: Bicarbonate (HCO - 3 ) 24 – 30 mEq/L Chloride (Cl -- ) 95 – 105 mEq/L Phosphate (PO 4 --- ) 2.8 – 4.5 mg/dL 8

9. Distribution of Cation and Anion in ECF & ICF (mEq/l) INTRA CELLULAR FLUID CATION Mg 1.1 Ca + 2.5 K+ 4 HCO3 – 24 Prot – 14 Others 6 PO4 - 2 Na+ 13 Mg+ 17 Prot - 40 HCO3- 10 Cl- 3 ANION ANION CATION EXTRA CELLULAR FLUID Na + 140 9 K + 140 Cl - 140 Phos - 107

10. Fluid & Electrolyte balance? 10 INTAKE = OUT PUT

11. Daily physiological fluid balance INTAKE Ingested liquid: 1500 ml Ingested food: 800 ml Metabolism: 200 ml Total 2500 ml / day OUTPUT Kidney: 1500 ml Skin loss: 600 ml GI: 100 ml Lung 300 ml Total 2500 ml Daily fluid balance of an adult 11

12. Movement of fluid & electrolytes A. Passive transport (no energy required): Osmosis : Fluid move from higher concentration to lower concentration Diffusion = Molecules move from higher concentration to lower (Concentration gradient) Filtration = Fluid and diffusible substances move together across a membrane; moving from ↑ pressure to ↓ pressure Hydrostatic pressure : Fluids moves from an area of higher pressure to area of lower pressure B. Active transport ( energy required): Sodium-Potassium Pump 12

13. Concentration of Body fluid Units of solute concentration are osmolarity and osmolality Osmolarity : Number of osmoles of solute per liter (L) of solution . It is expressed as osmol/L e.g 1 mol/L NaCl solution has an osmolarity of 2 osmol/L Osmolality : Number of osmoles of solute per kilogram(kg) of solvent . It is expressed as osmol/kg Normal serum osmolality=280-298 mosmol/kg 13

14. Clinical relevance of osmolality Calculation Serum osmolality (mosmol/kg) = Effective osmolality: O smotic force that is mediating the shift of water between the ECF and the ICF = The osmotic gap (osmolal gap): is the difference between the actual osmolality (measured by the laboratory) and the calculated osmolality A normal osmolal gap is < 10 mOsm/kg 14 2(Na + +K + ) mmol/l + Urea (mmol/l)+ Glucose (mmol/l) 2 x Na + (mmol/l )+ Glucose (mmol/l)

15. Regulation of Body Fluids Body fluid Homeostasis is maintained through Fluid intake Hormonal regulation Antidiuretic hormone(ADH) Renin-Angeotensin-Aldosterone Mechanism Natriuretic Peptides Fluid output 15

16. A. Fluid intake Intake is control by hypothalamic thirst center ↑ plasma osmolality of 1–2% ↓ plasma volume 10%–15% Baroreceptor input, angiotensin II, and other stimuli Moistening of the mucosa of the mouth and throat Activation of stomach and intestinal stretch receptors − ve 16

17. 1. Antidiuretic hormone(ADH) ADH: Secreted by the hypothalamus, and stored in the posterior pituitary gland ADH is released by, thrust, ↓ fluid volume, High serum osmolality Acton reabsorb water from collecting duct of kidney inhibit sweat glands to ↓ perspiration to conserve water acts on arterioles , causes constriction thus ↑ BP ADH is Inhibited by Excessive of fluid volume Low osmolality of serum 17 B. Hormonal regulation

18. 2. Renin- Angiotensin-Aldosterone Mechanism Low blood volume ↓Renal perfusion Angiotesinogen Angiotesin I Angiotensin II Aldosterone ACE ↑ Proximal renal tubule Systemic vasoconstriction ↑ Na & Water reabsorption ↑ Na & Water retention ↑ BP Renin ↑ ADH ↑H2O absorption Water and salt retention ↑ effective circulating volume ↑Renal perfusion Net effect Jaxtaglomerular apparatus

19. 3. Natriuretic Peptides Natriuretic Peptides Atrial Natriuretic Peptide(ANP ) from atria Brain Natriuretic Peptide(BNP) from ventricle Action Acts like a diuretic that causes sodium loss and inhibits the thirst mechanism Inhibit rennin release Inhibit the secretion of ADH and aldosterone Vasodilatation 19

20. C. Regulation by fluid output 20 Daily fluid losses: 2500 ml for an adult Kidney(Urine): 55% Skin: 30% Lung: 10% GI (Stool): 2-5%

21. Renal handling of Fluid & Electrolytes Substance Filtered Excreted Net reabsorption Water 180 L 1.5 L 98-99% Na+ 26,000 mmol 100-250 mmol >99% Cl- 21,000 mmol 100-250 >99% K+ 800 mmol 40-120 mmol >85-95% HCO3_ 4,800 mmol 0 mmol 100% Urea 54 gm 27-32 g 40-50% 21

22. Regulation of Electrolytes 22

23. Regulation of Sodium & Water Major cation in the ECF (N=135 - 145 mEq/L) Combines with chloride and bicarbonate to help regulate acid-base balance Recommended daily in take 2.5gm/day Kidney regulates sodium balance and is the principal site of sodium excretion Aldosterone helps in sodium and water conservation 23

24. Potassium regulation Major electrolyte and principle cation in the ICF Regulates metabolic activities Required for glycogen deposits in the liver and skeletal muscle Required for transmission of nerve impulses, normal cardiac conduction and normal smooth and skeletal muscle contraction Daily intake 1-2 mEq/kg Regulated by dietary intake and renal excretion Intestine absorbs about 90% of ingested potassium Regulate by renin-angiotensin-aldosterone mechanism 24

25. Calcium regulation 99% of calcium is in the bones and teeth 1% is in ECF 50% of calcium in the ECF is bound to protein (albumin) 40% is free & in ionized form-Ionized calcium Ca++ is needed for Bone and teeth formation Blood clotting Hormone secretion Cell membrane integrity Cardiac conduction Transmission of nerve impulses Muscle contraction 25

26. Anions Chloride (Cl - ) Major anion in ECF Follows sodium Bicarbonate (HCO 3 - ) Is the major chemical base buffer required for acid base balance Is found in ECF and ICF Regulated by kidneys 26

27. ELECTROLYTE IMBALANCES ● SODIUM IMBALANCE – HYPONATREMIA [< 135mEq/L serum Na] GI LOSSES [vomiting/diarrhea] KIDNEY DISEASE SKIN LOSS – PERSPIRATION PSYCHOGENIC POLYDYPSIA SIADH (SYNDROME OF INAPPROPRIATE ADH) 27

28. ELECTROLYTE IMBALANCES ● SODIUM IMBALANCES – HYPERNATREMIA [>145mEq/L] EXCESS SALT INTAKE INFUSION OF HYPERTONIC SALINE ( 3%, 5%) EXCESS ALDOSTERONE DIABETES INSIPIDUS [low ADH/thirst/dilute urine excreted – Na+ not excreted] DEHYDRATION [H2O follows Na+, but Na+ does not follow H2O] 28

29. ELECTROLYTE IMBALANCES ● POTASSIUM K+ – HYPOKALEMIA [<3.5mEq/L] Common, affects cardiac conductivity/ function POTASSIUM WASTING DIURETICS DIARRHEA, VOMITING ALKALOSIS [shifts into cells in exchange for H+] EXCESSIVE ALDOSTERONE SECRETION POLYURIA EXCESSIVE PERSPIRATION TREATMENT OF DKA WITH INSULIN [decreases serum potassium by redistributing it into cells] 29

30. ELECTROLYTE IMBALANCES ● POTASSIUM K+ – HYPERKALEMIA [>5mEq/L] Cardiac conduction, altered ECG, arrest RENAL FAILURE FLUID VOLUME DEFICIT CELL DAMAGE FROM BURNS, TRAUMA ADRENAL INSUFFICIENCY RAPID INFUSION OF STORED BLOOD POTASSIUM SPARING DIURETICS SALT SUBSTITUTES 30

31. ELECTROLYTE IMBALANCES ● Hypocalcemia [ionized Ca < 4.5 mEq/L OR total serum Ca < 8.5mEq/L] Illnesses affecting thyroid, parathyroid Renal failure [not excreting Phosphate] alcoholics, pancreatitis Neuromuscular and Cardiac sx ↑↑ reflexes, cramps, numbness/tingling 31

32. ELECTROLYTE IMBALANCES ● Hypercalcemia [serum Ionized Ca+ > 5.5 or total serum Ca > 10.5 mEq/L] Immobility, osteoporosis, neoplasm → bone loss of Ca into blood. Kidney stones, ↓ reflexes, N&V. 32

33. ELECTROLYTE IMBALANCES ● Magnesium [1.5-2.5 mEq/L] Malnutrition, malabsorption → ↓Mg [looks like ↓Ca] ↓ ↓ - Mg hyperactive reflexes Excess intake + renal problems → ↑Mg, ↓HR, RR, B/P, DTR ↓ [e.g. Sulfate in L&D] ● Chloride Follows Na+, Acid/base imbalance 33

34. Fluid Imbalance Fluid deficit -Dehydration Fluid excess- Hypervolemia 34

35. Dehydration Abnormal fluid loss causes fluid deficit called dehydration Conditions can leads to dehydration: Skin: Fever, under heater, heat exhaustion, burn GI: Gastroenteritis , fistula, intestinal obstruction Lung: Tachypnea Kidney: Polyuria e.g. diabetes Miscellaneous: Surgical drain, third spacing 35

36. According to serum Sodium (Na) concentration: Isonatremic (Isotonic)=S. Na 135-150 mmol/l Hyponatremic (Hypotonic)= S. Na <135 mmol/l Hypernatremic (Hypertonic)= S. Na>150 mmol/l Types of dehydration 36

37. What types of IV fluid ? Types of IVF used: Normal saline (0.9% NaCl/L) = 154 mEq Na + /L One-half NS (0.45% NaCl/L) = 77 mEq Na + /L One-third NS (0.33% NaCl/L) = 57 mEq Na + /L One-quarter NS (0.25% NaCl/L) = 38 mEq Na + /L One fifth NS(0.18% Nacl) = 30 mmol/l Ringer’s lactate= Na + 130 mmol/l, K + 4 mmol/l, Cl - 109 mmol/l, bicarb 28 mmol/l , and Ca ++ 3 mg/dl ) 37

38. REGULATION OF ACID-BASE BALANCE 38 — BUFFER A SUBSTANCE THAT CAN EITHER ABSORB OR RELEASE A HYDROGEN ION (H+) — ARTERIAL pH REFLECTS TH CONCENTRATION OF HYDROGEN IONS IN THE BLOOD — THE pH SCALE MEASURES THE ACIDITY OR ALKALINITY OF A FLUID NORMAL RANGE FOR ARTERIAL BLOOD 7.35 – 7.45

39. REGULATION OF ACID-BASE BALANCE BIOLOGICAL REGULATION OF Ph ● BUFFERING SYSTEMS ★ HYDROGEN IONS ARE ABSORBED OR RELEASED BY THE CELLS. — SWITCH PLACES WITH POTASSIUM. ★ HEMOGLOBIN-OXYHEMOGLOBIN SYSTEM. ★ CHLORIDE SHIFT WITHIN RBC. 39

40. REGULATION OF ACID-BASE BALANCE PHYSIOLOGICAL : Lungs, Kidneys LUNGS Early response •↑ HYDROGEN & CARBON DIOXIDE [acidosis] Stimulates ↑ Respiratory rate, depth → exhaled CO2 •↓ Co2 & H+ [alkalosis] → retain CO2 by ↓RR ♡ EXAMPLES – DIABETIC KETOACIDOSIS – CO2 RETAINING PATIENTS WITH COPD 40

41. REGULATION OF ACID-BASE BALANCE ♡ Takes longer/lasts longer – Hours to days ♡ Increased or decreased production of Bicarb, excretion of H+ by ammonia formation, phosphoric acid. ♡ Acid excess [acidosis] → reabsorption of bicarb, ♡ Phosphate + H+ = H3PO4 and NH3- + H+ = NH4 → excretion of H+, lowers acid 41

42. TYPES OF ACID-BASE IMBALANCE RESPIRATORY ACIDOSIS RESPIRATORY ALKALOSIS METABOLIC ACIDOSIS METABOLIC ALKALOSIS Name reflects underlying cause, compensation 42

43. Blood Gases & Acid/Base Balance Normal arterial blood pH: 7.35-7.45 Acidosis: pH < 7.35 Alkalosis: pH > 7.45 Respiratory Acidosis/Alkalosis – Reflected in PaCO2: [35-45 mg Hg] ▪︎ resp rate from any cause blows off CO2 ▪︎ Resp rate from any cause conserves CO2 – Compensation is via kidneys 43

44. Blood Gases & Acid/Base Balance Metabolic Acidosis/Alkalosis – Base Excess: amount of buffer [Hgb & bicarb] – Normal : -2mEq/L - +2mEq/L [HCO3- 22-26] – Alkalosis: BE > +2mEq/L or Bicarb>26 ▪︎[from acid loss/ vomiting, gastric suction] – Acidosis: BE< -2 mEq/L or Bicarb < 22 ▪︎[e.g. from diarrhea, renal disease] – Compensation is via Respiratory system 44